Question

Let’s say I have a string with my class name inside:

mystring = "CDialogChild";

I would like to create an object of the type name written in my string.
I’d like to do something like:

CDialogParent dlg = CDialogParent(mystring);

My new dlg is now created as type CDialogChild and I can use its methods:

dlg.mycdialogchild_method();

Answer 1

There is nothing in C++ that will provide you such feature (called Reflection).

However, if your classes are of finite number, you can do some kind of mapping with some factories :

class IClassFactory // base interface
{ public: 
    virtual ~IClassFactory(){} 
}

template< class T >
class ClassFactory { 
/* whatever necessary here*/
public:

  T* create();
};


class ClassManager
{
public:

   void add( std::string name, IClassFactory* factory ) { m_map[name] = factory; }

   ACommonBaseClass* create( std::string class_name ) { return m_map[class_name]->create(); } // this line isn't correct but you get the idea

private:

   std::map< std::string, IClassFactory* > m_map;

};

Or something similar (this is written quickly).

Alternatively you could work with a scripting language that would allow Reflection, but that would add a whole layer to your application. Scripting languages that might be of interest for embedding with c++ : ChaiScript, Falcon, Lua, Python, AngelScript, MonkeyScript, Io, …